Electric lamp



(N0 Model.)

"H. S. MAXIM.

vlILHG'RIC LAMP.

Patented Jan. 17,1882.

enabled to construct a better and more durajoints, and to their inner orsmaller ends the suitable switch operating to'close or break the.forming a part thereot'.

. is furnished with a stopper, which fits tightlyl into the open neck.The stopper, which is of applied.

.iuclosing-globe, A, in which are several' car- UNITED STATES PATENTOEiEICEf HiEAiii s. MAXIM, or" BROOKLYN, NEW vonk.

ELECTRIC LAMP.

SPECIFICATION forming part of' Letters Patent No. 252,391, dated January17, 1852,

Appncmim'i sied Myie, 1881. (No muriel.;

To all rwhom it may concern:

Be it known that I, HIRAM S. MAXIM, ot' Brooklyn, in the county of Kingsand State of New York,have invented certain new and usei'ul Improvementsin Electiic Lamps, of which the following is a specification, referencebcing had to the drawings accompanying and ln former applications tiledby me I have shown incandescent electric lamps composed of a transparentexhausted receiver surrounding one or more strips of carbon, which areincluded in the lelectric circuit by attachment tothe metal conductorsintroducing the current into thesaid receiver. One ofthe methodsproposed by me for bringing these wires into the globe may be stated ingeneral terms to consist in sealing or otherwise embeddingthe same in aplug or stopper, which tits the open neck of a glass globe bya groundjoint. Over this method my present invention is designed as animprovement, inasmuch as by it I am ble lamp at a greatly reduced cost.

According to my present invention .the globe glass, is pierced at two ormore points by slightly -tapering holes formed during the course ofmolding or by subsequent drilling. In the. holes are fitted steel plugs,of corresponding shape, and of such length that the ends project oneither side of the stopper. The plugs are fitted to the glass by groundsupportingconductors are attached, while the outer ends serve ascircuit-connections for a circuit through the lamp. l The accompanyingdrawings are referred to for au understanding of the invention.

Figures lv and 2 represent in central vertical section lamps to whichmy'inventiou is Similar letters in both gures refer to'correspondingparts.

The lamp illustrated in Fig. l consists-ot' an bons, D D, whose ends areunited to the sanne mass of conducting material, D. Into the open mouthofthe globe A is fitted,"by grind ing, a stopper, B', of glass orequivalent material. Through the stopper are formed many conicalperlorations as the numberot' carbon conductors requires, and into thesethe steel plugs E are iitted by grinding, so that the joints formedshall be perfectly air-tight. To the smaller ends ot' the plugs theconductors, of platinum or copper, C Uf, are attached in any way tosecure a good electrical contact. vIn the. present instance they arescrewed into threaded holes in the ends of the plugs. To the conductorsC U the carbons D D are clamped, theirfree ends being-united to a smallblock of carbon or metal, D', from which a conductor, G, leads tov oneot' the steel plugs. From the shape of the plugs and the manner iu whichthey are fitted to the stopper it followsthat as the air isexhaustedfrom the globe in the usual way the atmospheric pressure tends to drawthem in the tighter. As an additional precaution the spaces about theprojecting ends of the plugs on the outside of the stopper are filled inwith cement, wax, or a similar substance.

The projecting ends of the steel plugs may be utilized ascircuit-connections in conjunction with any suitable circuit-maker orswitch, and it is evident from the number and disposition of the plugsand conductors attached thereto that one, all, or any desired portion ofthe conductors, may be rendered incandescent at a time by making theproper connections. The apparatus which l design using for accomplishing this purpose is not illustrated herein, asl intend making a separateapplication there for.

The ground steel plugs as a means of conveying the current through astopper into an air-tight lamp-globe, though described in connectionwith a lamp of peculiar kind, are applicable to anyforin of lampin whichthe globe inclosing the light-giving part is closed by a plug or stopper'of vitreous material, and this I have illustrated in Fig. 2, where thelamp is shown as containing a'single and coutiiiuous conductor with twoplugs, the arrangement being substantially that of the ordinary forms oflamp now in use; nor is it essential to this part of my invention inwhat manner the carbons or their supporting-conductors are connectedwith the steel plugs, nor by what means the circuit is complet ed fromthe line-Wires io the steel plugs, as it is obviously possible to varythe construction of the lamp in these particulars almost indefinitely.

Having now described my invention, what I claim is 1. The combination,in an electricla-mp, of a transparent globe surrounding the source oflight and an airtight non-conducting plug or stopper closing the sameand containing two vor more conical steel Wires or plugs ground intoperforations through the material of which said stopper is composed, andin electrical connection with the carbon conductors, as described.

2. The combination, with the transparentglobe of an incandesc ntelectric lamp, of a glass stopper fitting the same by a ground joint andcontaining two or more conical steel wires or pl ugs ground into andpassing through correspondingly-shaped perforations in the said stopperand suitably connected to the supportingconductors of the carbon strip,as described.

In testimony whereof I lmvehereuntoafixed my signature this 10th day ofMay, 1881.

HIRAM S. MAXIM.

WVitnesses W. M. ALLMRE,

PARKER W. PAGE.

